It is useful for runners, and especially endurance runners, to improve their running efficiency. If a runner can improve their running form to run more efficiently, they can improve running speed and running distance. A runner may attempt to determine their running efficiency by evaluating the way that they feel during or after a run. However, factors other than the runner's form may affect the way that the runner feels. For example, weather conditions, diet, sickness and other factors may affect the way a runner feels. Accordingly, it may be difficult for a runner to get an accurate assessment of how efficiently they are running, or how a change in their running form is affecting their running efficiency.
U.S. Pat. No. 7,736,273 to Cox et al., filed 10 Mar. 2009, incorporated herein in its entirety by this reference, describes an interface box removably disposed on incoming power wiring of a treadmill, and describes utilizing electronic signature analysis (ESA) for gait analysis. However, Cox et al. does not describe how one might determine a running efficiency of a runner with the ESA, or how one might determine interaction forces between the runner and the treadmill with the ESA. Rather, for analyzing a runner's athletic performance, Cox et al. describes that one could establish characteristic ‘signatures’ of elite runners and compare them with other developing runners.
In view of the foregoing, there is a need for devices and methods that may effectively measure, calculate, and report running efficiency and/or interaction forces. Additionally, there is a need for devices and methods that may facilitate improvement in running efficiency.